CN113265085B - Polymethylsilsesquioxane-polyimide composite aerogel material and preparation and application thereof - Google Patents
Polymethylsilsesquioxane-polyimide composite aerogel material and preparation and application thereof Download PDFInfo
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- 239000004964 aerogel Substances 0.000 title claims abstract description 73
- 239000002131 composite material Substances 0.000 title claims abstract description 68
- 239000000463 material Substances 0.000 title claims abstract description 44
- 239000004642 Polyimide Substances 0.000 title claims abstract description 35
- 229920001721 polyimide Polymers 0.000 title claims abstract description 35
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 229920005575 poly(amic acid) Polymers 0.000 claims abstract description 60
- 239000000243 solution Substances 0.000 claims abstract description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000001035 drying Methods 0.000 claims abstract description 28
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000002253 acid Substances 0.000 claims abstract description 26
- 239000011240 wet gel Substances 0.000 claims abstract description 22
- 239000012266 salt solution Substances 0.000 claims abstract description 21
- 239000007787 solid Substances 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 18
- BFXIKLCIZHOAAZ-UHFFFAOYSA-N methyltrimethoxysilane Chemical compound CO[Si](C)(OC)OC BFXIKLCIZHOAAZ-UHFFFAOYSA-N 0.000 claims abstract description 17
- -1 diamine compound Chemical class 0.000 claims abstract description 16
- 238000000352 supercritical drying Methods 0.000 claims abstract description 16
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 15
- 235000011114 ammonium hydroxide Nutrition 0.000 claims abstract description 15
- 239000002244 precipitate Substances 0.000 claims abstract description 15
- 150000003839 salts Chemical class 0.000 claims abstract description 15
- 239000004952 Polyamide Substances 0.000 claims abstract description 11
- 238000004108 freeze drying Methods 0.000 claims abstract description 11
- 229920002647 polyamide Polymers 0.000 claims abstract description 11
- 239000004094 surface-active agent Substances 0.000 claims abstract description 10
- 239000002904 solvent Substances 0.000 claims abstract description 5
- 238000005406 washing Methods 0.000 claims abstract description 5
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 22
- 238000003756 stirring Methods 0.000 claims description 17
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 15
- 229960000583 acetic acid Drugs 0.000 claims description 11
- 239000012362 glacial acetic acid Substances 0.000 claims description 11
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 10
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 5
- WKDNYTOXBCRNPV-UHFFFAOYSA-N bpda Chemical compound C1=C2C(=O)OC(=O)C2=CC(C=2C=C3C(=O)OC(C3=CC=2)=O)=C1 WKDNYTOXBCRNPV-UHFFFAOYSA-N 0.000 claims description 5
- WOWHHFRSBJGXCM-UHFFFAOYSA-M cetyltrimethylammonium chloride Chemical compound [Cl-].CCCCCCCCCCCCCCCC[N+](C)(C)C WOWHHFRSBJGXCM-UHFFFAOYSA-M 0.000 claims description 5
- 235000006408 oxalic acid Nutrition 0.000 claims description 5
- HLBLWEWZXPIGSM-UHFFFAOYSA-N 4-Aminophenyl ether Chemical compound C1=CC(N)=CC=C1OC1=CC=C(N)C=C1 HLBLWEWZXPIGSM-UHFFFAOYSA-N 0.000 claims description 4
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 4
- CBCKQZAAMUWICA-UHFFFAOYSA-N 1,4-phenylenediamine Chemical compound NC1=CC=C(N)C=C1 CBCKQZAAMUWICA-UHFFFAOYSA-N 0.000 claims description 3
- VLDPXPPHXDGHEW-UHFFFAOYSA-N 1-chloro-2-dichlorophosphoryloxybenzene Chemical compound ClC1=CC=CC=C1OP(Cl)(Cl)=O VLDPXPPHXDGHEW-UHFFFAOYSA-N 0.000 claims description 3
- KHYXYOGWAIYVBD-UHFFFAOYSA-N 4-(4-propylphenoxy)aniline Chemical compound C1=CC(CCC)=CC=C1OC1=CC=C(N)C=C1 KHYXYOGWAIYVBD-UHFFFAOYSA-N 0.000 claims description 3
- VQVIHDPBMFABCQ-UHFFFAOYSA-N 5-(1,3-dioxo-2-benzofuran-5-carbonyl)-2-benzofuran-1,3-dione Chemical compound C1=C2C(=O)OC(=O)C2=CC(C(C=2C=C3C(=O)OC(=O)C3=CC=2)=O)=C1 VQVIHDPBMFABCQ-UHFFFAOYSA-N 0.000 claims description 3
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 5
- 239000008367 deionised water Substances 0.000 description 16
- 229910021641 deionized water Inorganic materials 0.000 description 16
- 238000010438 heat treatment Methods 0.000 description 10
- 229920003217 poly(methylsilsesquioxane) Polymers 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000000499 gel Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000013001 point bending Methods 0.000 description 2
- 238000006068 polycondensation reaction Methods 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- QYIMZXITLDTULQ-UHFFFAOYSA-N 4-(4-amino-2-methylphenyl)-3-methylaniline Chemical compound CC1=CC(N)=CC=C1C1=CC=C(N)C=C1C QYIMZXITLDTULQ-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229920002396 Polyurea Polymers 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 150000001335 aliphatic alkanes Chemical group 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000005815 base catalysis Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 1
- ZLNAFSPCNATQPQ-UHFFFAOYSA-N ethenyl-dimethoxy-methylsilane Chemical compound CO[Si](C)(OC)C=C ZLNAFSPCNATQPQ-UHFFFAOYSA-N 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
- B01J31/06—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing polymers
-
- B01J35/30—
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2201/00—Foams characterised by the foaming process
- C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
- C08J2201/05—Elimination by evaporation or heat degradation of a liquid phase
- C08J2201/0502—Elimination by evaporation or heat degradation of a liquid phase the liquid phase being organic
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2205/00—Foams characterised by their properties
- C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
- C08J2205/026—Aerogel, i.e. a supercritically dried gel
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2383/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
- C08J2383/04—Polysiloxanes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2479/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2461/00 - C08J2477/00
- C08J2479/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C08J2479/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
Abstract
The invention relates to a polymethylsilsesquioxane-polyimide composite aerogel material, and preparation and application thereof, wherein the preparation comprises the following steps: (a) dissolving a diamine compound and a dianhydride compound in a solvent in sequence, adding water to precipitate polyamide acid precipitate, washing the obtained polyamide acid precipitate, freeze-drying to obtain pure polyamide acid solid, dissolving the pure polyamide acid solid in water, and adding ammonia water to obtain polyamide acid salt solution; (b) taking a weak acid solution, sequentially adding a surfactant, methyltrimethoxysilane and a polyamic acid salt solution to obtain sol, and drying the sol to obtain polymethylsilsesquioxane-polyamic acid salt composite wet gel; (c) and (3) replacing the composite wet gel with alcohol for several times, and then performing alcohol supercritical drying to finally obtain the polymethylsilsesquioxane-polyimide composite aerogel. Compared with the prior art, the composite aerogel prepared by the invention has excellent mechanical property and thermal property, and has simple process and low equipment requirement.
Description
Technical Field
The invention belongs to the technical field of aerogel preparation, and particularly relates to a polymethylsilsesquioxane-polyimide composite aerogel material, and preparation and application thereof.
Background
The aerogel is a very representative porous material, and the ultrahigh porosity endows the aerogel material with physical characteristics of low density, low thermal conductivity, high specific surface area and the like. The unique physical properties enable the aerogel material to have extremely high application potential in a plurality of fields, such as the fields of heat preservation and insulation, high-temperature catalysis, aerospace, hydrogen storage and energy storage and the like. However, the abundant porous structure also gives the defect of poor mechanical properties of the aerogel. Aerogels are extremely prone to cracking under the action of external forces and are extremely fragile, which greatly limits the range of applications for aerogel materials. In order to overcome the brittleness of aerogel materials, researchers have tried to compound an aerogel framework with organic polymers, such as polyurea, epoxy resin, isocyanate, etc., and increase the contact points between particles by coating the framework periphery, thereby increasing the compressive strength. In addition, the mechanical property of the aerogel material can be remarkably improved by adopting a silicon source containing organic substituents as a precursor to prepare the organic siloxane aerogel, and the silicon source comprises methyltrimethoxysilane, dimethoxymethylvinylsilane, vinyltrimethoxysilane and the like. In addition, the compressibility, flexibility and machinability of the aerogel material can be remarkably improved by introducing organic components such as methyl and alkane chains into the aerogel framework. Although the three methods can obviously improve the mechanical properties of the aerogel material, the introduction of the organic component also greatly reduces the thermal stability of the aerogel, and the material can be decomposed, shrunk, cracked and the like at the temperature higher than 200 ℃, so that the aerogel material prepared by the method can not be applied to the high-temperature field. Therefore, the preparation of the aerogel material with excellent mechanical property and thermal property has extremely important practical significance.
Disclosure of Invention
The invention aims to provide a preparation method of a polymethylsilsesquioxane-polyimide composite aerogel material.
The purpose of the invention is realized by the following technical scheme:
a preparation method of a polymethylsilsesquioxane-polyimide composite aerogel material specifically comprises the following steps:
(a) dissolving a diamine compound and a dianhydride compound in a solvent in sequence, adding water to precipitate a polyamic acid precipitate after uniformly stirring, washing the obtained polyamic acid precipitate for a plurality of times, freeze-drying to obtain a pure polyamic acid solid, dissolving the pure polyamic acid solid in water, adding ammonia water, and stirring to obtain a polyamic acid salt solution, wherein the ammonia water has the function of dissolving the pure polyamic acid solid so as to form the polyamic acid salt solution, and the chemical reaction generated in the step is shown in the following formula I (4, 4 ' -diaminodiphenyl ether represents a diamine compound, and 3,3 ', 4,4 ' -biphenyl tetracarboxylic dianhydride represents a dianhydride compound);
(b) taking a weak acid solution, sequentially adding a surfactant, methyltrimethoxysilane and a polyamic acid salt solution to obtain sol, and standing the sol in an oven to obtain polymethylsilsesquioxane-polyamic acid salt composite wet gel, wherein the weak acid environment provided by the weak acid solution promotes the hydrolysis reaction of the methyltrimethoxysilane, the surfactant inhibits the phase separation of the methyltrimethoxysilane, and the polyamic acid salt solution promotes the polycondensation reaction of the methyltrimethoxysilane and provides the polyamic acid salt for a sol system;
(c) and (b) replacing the composite wet gel obtained in the step (b) with alcohol for several times, and then carrying out alcohol supercritical drying to realize thermal imidization reaction of polyamic acid salt (specifically, in the drying process, the polyamic acid salt is dehydrated through thermal imidization reaction at high temperature to form polyimide), and finally obtaining the polymethylsilsesquioxane-polyimide composite aerogel.
In the step (a), the diamine compound is selected from one or more of 4,4 ' -diaminodiphenyl ether, p-phenylenediamine, 2 ' -dimethylbenzidine or 2,2 ' -bis [4- (4-aminophenoxy) phenyl ] propane.
In the step (a), the dianhydride compound is one or more selected from 3,3 ', 4, 4' -biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, or 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride.
In the step (a), the solvent is selected from one or more of 1-methyl-2-pyrrolidone or dimethylacetamide.
In the step (a), the molar ratio of the diamine compound to the dianhydride compound is 1: 1.
In the step (a), the addition ratio of the pure polyamic acid solid, water and ammonia water is (0.1-1.0) g, (20-25) ml, (0.3-1.0) ml, preferably (0.3-1.0) g, (20-25) ml, (0.4-0.8) ml. The water here refers to the water added for the second time.
In the step (a), the obtained polyamic acid precipitate is washed with deionized water for 12-15 times.
In the step (a), the temperature of freeze drying is-80 to-60 ℃, and the freeze drying is carried out twice, wherein the time of freeze drying for each time is 15-20 hours.
In the step (b), the weak acid is selected from one of hydrofluoric acid, glacial acetic acid or oxalic acid. In step (b), the surfactant is selected from one or more of cetyltrimethylammonium chloride or cetyltrimethylammonium bromide.
In the step (b), the addition amount ratio of the weak acid solution, the surfactant, the methyltrimethoxysilane and the polyamic acid salt solution is (20-35) ml, (0.2-1.0) ml, (4-10) ml, (0.5-5) ml, preferably (25-35) ml, (0.4-0.8) ml, (6-10) ml and (1-5) ml. The specific concentration of polyamic acid salt in the polyamic acid salt solution can be obtained according to the addition amounts of pure polyamic acid solid, water, and ammonia in step (a) and the equilibrium constant of the reaction.
In the step (b), the concentration of the weak acid in the weak acid solution is 5-10 mmol/L, preferably 5.2-10 mmol/L.
In the step (b), the temperature of the oven is set to be 45-65 ℃, preferably 45-60 ℃, and the standing time is 24-36 hours. The term "standing" in this step means that the polycondensation reaction of methyltrimethoxysilane is accelerated in the environment provided by the oven, and the sol finally reaches the gel point to form a gel.
In the step (c), the composite wet gel obtained in the step (b) is replaced by alcohol for 5-6 times.
In the step (c), the drying temperature is 265-290 ℃, preferably 268-290 ℃, the drying pressure is 10-14 MPa, preferably 11-14 MPa, and the drying time is 12-15 h, preferably 13-15 h.
In the step (c), supercritical drying is carried out in an autoclave, the supercritical high-temperature environment of alcohol provides conditions for thermal imidization of polyamic acid salt, and the polyamic acid salt can form polyimide through a dehydration process.
It is another object of the present invention to provide a composite aerogel material prepared by the above-described preparation method. In terms of mechanical properties, the three-point bending radial deformation amount of the composite aerogel material prepared by the invention can reach 27%, and the composite aerogel material can rebound by 54% after being compressed to 80% of the original height, and has good machinability. In terms of thermal properties, the thermal conductivity of aerogels at room temperature is as low as 0.021W/m.K. The material still keeps the complete shape after being subjected to heat treatment at 450 ℃ for 30min, does not generate heat shrinkage and still has compressibility of 44%; the shape and the porous structure are still kept after the heat treatment at 1050 ℃ for 30min, and the compressibility is still 13.5%. In addition, the material has extremely low density and super hydrophobicity, and the density is as low as 0.08g/cm3The drainage angle is up to 151 deg..
Another object of the present invention is to provide a use of the composite aerogel material as described above, specifically: the composite aerogel material is used as a heat-insulating material or a catalyst carrier used at high temperature.
According to the invention, a precursor blending method and an acid-base catalysis method are adopted, so that ether bonds, carbonyl groups and carboxyl groups in polyamic acid salt and unhydrolyzed hydroxyl groups in polymethylsilsesquioxane are combined through hydrogen bonds to form composite gel, and then the polymethylsilsesquioxane-polyimide composite aerogel is prepared through an alcohol supercritical drying process by a one-step method.
Compared with the prior art, the invention has the following advantages: the polymethylsilsesquioxane-polyimide composite aerogel prepared by the invention has the advantages of low density, excellent mechanical property, low thermal conductivity, outstanding hydrophobic property and temperature resistance, and a series of excellent physical properties such as excellent mechanical property and thermal property, is a thermal insulation material with excellent performance, has great potential to be used as a catalyst carrier used at high temperature, and has extremely high application value in the future. The preparation method provided by the invention has the advantages of low energy consumption, low cost, simple process and low equipment requirement, the synthesis of the polyimide can be realized in the alcohol supercritical drying process, no additional dehydration reaction is needed, the preparation of a large-size sample can be realized by using the method, and the large-scale production and practical application of the material can be promoted.
Drawings
FIG. 1 is a diagram of a polymethylsilsesquioxane-polyimide composite aerogel prepared in example 4 processed into an arbitrary shape;
FIG. 2 is a graph comparing polymethylsilsesquioxane-polyimide composite aerogel prepared in example 4 (top) and pure polymethylsilsesquioxane aerogel prepared in comparative example 1 (bottom) before and after heat treatment at 450 ℃;
FIG. 3 is a uniaxial compressive stress-strain curve of the polymethylsilsesquioxane-polyimide composite aerogel prepared in example 4 after heat treatment at 450 ℃.
Detailed Description
The present invention is described in detail below with reference to the attached drawings and specific examples, which are further illustrative of the present invention and do not limit the scope of the present invention.
Example 1
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the preparation method comprising the following steps:
(1) 1.6g of 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride (molecular weight of 322.23g/mol) and 0.5g of p-phenylenediamine (molecular weight of 108.14g/mol) are sequentially dissolved in 23ml of 1-methyl-2-pyrrolidone, and after uniform stirring, 500ml of deionized water is added to separate out a polyamic acid precipitate. The obtained polyamic acid precipitate is washed by deionized water for 12 times, and then is frozen and dried twice at the temperature of minus 60 ℃ for 15 hours each time, so that pure polyamic acid solid is prepared. 0.3g of pure polyamic acid solid is dissolved in 20ml of deionized water, 0.4ml of ammonia water is added into the solution, and the solution is stirred for a certain time to obtain the polyamic acid salt solution.
(2) 10. mu.L of hydrofluoric acid was dissolved in 100ml of deionized water to prepare a hydrofluoric acid solution having a concentration of 5.7 mmol/L. 25ml of hydrofluoric acid solution was taken, and 0.4g of cetyltrimethylammonium bromide was added thereto. After stirring well, 6ml of methyltrimethoxysilane was added. And after stirring uniformly again, adding 2ml of polyamic acid salt solution into the obtained solution to obtain sol, and standing the obtained sol in a 50 ℃ oven for 24 hours to obtain the polymethylsilsesquioxane-polyamic acid salt composite wet gel.
(3) And (3) replacing the composite wet gel obtained in the step (2) with alcohol for 5 times, placing the composite wet gel in an autoclave for alcohol supercritical drying, wherein the drying temperature is 270 ℃, the drying pressure is 12MPa, the drying time is 13h, and the polymethylsilsesquioxane-polyimide composite aerogel can be prepared after the alcohol supercritical drying is finished.
Example 2
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the preparation method comprising the following steps:
(1) 1.5g of 3,3 ', 4,4 ' -biphenyl tetracarboxylic dianhydride (molecular weight is 294.22g/mol) and 2.1g of 2,2 ' -bis [4- (4-aminophenoxy) phenyl ] propane (molecular weight is 410.51g/mol) are sequentially dissolved in 25ml of 1-methyl-2-pyrrolidone, and after the mixture is uniformly stirred, 600ml of deionized water is added to separate out a polyamide acid precipitate. Washing the obtained polyamic acid precipitate for 15 times, and freeze-drying at-70 ℃ for 16 hours twice to obtain pure polyamic acid solid. 0.6g of pure polyamic acid solid is dissolved in 23ml of deionized water, 0.5ml of ammonia water is added, and the solution is stirred for a certain time to obtain the polyamic acid salt solution.
(2) A glacial acetic acid solution with a concentration of 8.7mmol/L was prepared by dissolving 70. mu.L of glacial acetic acid in 140ml of deionized water. 30ml of glacial acetic acid solution were taken and 0.6g of cetyltrimethylammonium chloride were added thereto. After stirring well, 7ml of methyltrimethoxysilane was added. After stirring again uniformly, 1 ml of polyamic acid salt solution was added to the obtained solution to obtain a sol. And (3) placing the obtained sol into an oven at 60 ℃ and standing for 30h to obtain the polymethylsilsesquioxane-polyamic acid salt composite wet gel.
(3) And (3) replacing the composite wet gel obtained in the step (2) with alcohol for 6 times, placing the composite wet gel in an autoclave for alcohol supercritical drying, wherein the drying temperature is 276 ℃, the drying pressure is 13MPa, the drying time is 14h, and the polymethylsilsesquioxane-polyimide composite aerogel can be prepared after the alcohol supercritical drying is finished.
Example 3
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the preparation method comprising the following steps:
(1) 1.1g of pyromellitic dianhydride (molecular weight is 218.12g/mol) and 1.1g of 2, 2' -dimethylbenzidine (molecular weight is 212.29g/mol) are sequentially dissolved in 18ml of dimethylacetamide, and are added with 500ml of deionized water after being uniformly stirred to separate out a polyamic acid precipitate. Washing the obtained polyamic acid precipitate for 15 times, and freeze-drying at-80 deg.C for 20 hr twice to obtain pure polyamic acid solid. 0.8g of pure polyamic acid solid is dissolved in 25ml of deionized water, 0.6ml of ammonia water is added, and the solution is stirred for a certain time to obtain the polyamic acid salt solution.
(2) mu.L of oxalic acid was dissolved in 50ml of deionized water to prepare an oxalic acid solution having a concentration of 5.2 mmol/L. 30ml of oxalic acid solution was taken, and 0.8g of cetyltrimethylammonium bromide was added thereto. After stirring well, 6ml of methyltrimethoxysilane was added. After stirring again uniformly, 3ml of polyamic acid salt solution was added to the obtained solution to obtain a sol. And (3) placing the obtained sol into an oven at 55 ℃ and standing for 30h to obtain the polymethylsilsesquioxane-polyamic acid salt composite wet gel.
(3) And (3) replacing the composite wet gel obtained in the step (2) with alcohol for 5 times, placing the composite wet gel in an autoclave for alcohol supercritical drying, wherein the drying temperature is 268 ℃, the drying pressure is 11MPa, the drying time is 13h, and the polymethylsilsesquioxane-polyimide composite aerogel can be prepared after the alcohol supercritical drying is finished.
Example 4
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the preparation method comprising the following steps:
(1) 1.6g of 3,3 ', 4,4 ' -biphenyl tetracarboxylic dianhydride (molecular weight of 294.22g/mol) and 1.1g of 4,4 ' -diaminodiphenyl ether (molecular weight of 200.24g/mol) are sequentially dissolved in 20ml of 1-methyl-2-pyrrolidone, and after uniform stirring, 400ml of deionized water is added to separate out a polyamic acid precipitate. The polyamic acid precipitate obtained was washed 15 times and then freeze-dried twice at-60 ℃ for 16 hours each time to give a pure polyamic acid solid. 1.0g of pure polyamic acid solid is dissolved in 25ml of deionized water, 0.8ml of ammonia water is added into the solution, and the solution is stirred for a certain time to obtain the polyamic acid salt solution.
(2) mu.L of glacial acetic acid was dissolved in 100ml of deionized water to prepare a glacial acetic acid solution with a concentration of 10 mmol/L. 35ml of glacial acetic acid solution were taken and 0.8g of cetyltrimethylammonium chloride were added thereto. After stirring well, 10ml of methyltrimethoxysilane was added. And after stirring uniformly again, adding 5ml of polyamic acid salt solution into the obtained solution to obtain sol, and standing the obtained sol in an oven at the temperature of 45 ℃ for 36 hours to obtain the polymethylsilsesquioxane-polyamic acid salt composite wet gel.
(3) And (3) replacing the composite wet gel obtained in the step (2) with alcohol for 6 times, and placing the composite wet gel in an autoclave for alcohol supercritical drying. The drying temperature is 290 ℃, the drying pressure is 14MPa, the drying time is 15h, and the polymethylsilsesquioxane-polyimide composite aerogel can be prepared after the ethanol supercritical drying is finished. The density of the composite aerogel is 0.08g/cm3The drainage angle is up to 151 deg..
In terms of mechanical properties, the composite aerogel can rebound by 54% after being compressed to 80% of the original height, and the radial deformation in a three-point bending test is up to 27%. The composite aerogel is taken for mechanical processing, and can be used for obtaining objects in various shapes as shown in figure 1, namely the aerogel material has good processing performance and can be processed into any shape according to the requirements.
In terms of thermal property, the thermal conductivity of the material at room temperature can reach 0.021W/m.K at the lowest. The composite aerogel is taken to be subjected to heat treatment, the treatment results are shown in figures 2 and 3, as can be seen from the entity comparison graph of figure 2, after the composite aerogel is subjected to heat treatment at 450 ℃ for 30min, the composite aerogel still keeps the complete shape and does not generate heat shrinkage, as can be seen from figure 3, the composite aerogel still has the compressibility of 44% after being subjected to heat treatment at 450 ℃ for 30min, and the compressive strength is 0.061 MPa. The composite aerogel still keeps complete shape and porous structure after being subjected to heat treatment at 1050 ℃ for 30min, and still has compressibility of 13.5%.
Comparative example 1
A pure polymethylsilsesquioxane aerogel is prepared by the following steps: mu.L of glacial acetic acid was dissolved in 100ml of deionized water to prepare a glacial acetic acid solution with a concentration of 10 mmol/L. 35ml of glacial acetic acid solution were taken and 0.8g of cetyltrimethylammonium chloride were added thereto. After stirring well, 10ml of methyltrimethoxysilane was added. And after stirring uniformly again, adding 5ml of ammonia water solution into the obtained solution to obtain sol, placing the obtained sol into a 45 ℃ oven, standing for 36h to obtain pure polymethylsilsesquioxane wet gel, replacing the wet gel with alcohol for 6 times, and placing the wet gel into an autoclave for alcohol supercritical drying. The drying temperature is 290 ℃, the drying pressure is 14MPa, the drying time is 15h, and the pure polymethylsilsesquioxane aerogel can be prepared after the ethanol supercritical drying is finished. Wherein the ammonia water solution is prepared by dissolving 0.8ml of ammonia water in 25ml of deionized water and uniformly stirring. The aerogel is taken to be subjected to heat treatment, the treatment result is shown in figure 2, and the phenomena of decomposition, crushing, cracking and the like of the aerogel can be seen from the material comparison graph of figure 2 after the aerogel is subjected to heat treatment at 450 ℃.
Example 5
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the preparation method comprising the following steps of (a) dissolving 0.1g of pure polyamic acid solid in 20ml of water, adding 0.3ml of ammonia water, in step (b) taking 20ml of weak acid solution, taking 0.2g of surfactant, 4ml of methyltrimethoxysilane and 0.5ml of polyamic acid salt solution, wherein the drying temperature is 65 ℃, and the drying pressure is 14MPa in step (c), and the rest is the same as in example 1.
Example 6
A polymethylsilsesquioxane-polyimide composite aerogel material with both mechanical property and thermal property is prepared by the following preparation method, except that in the step (a), 1.0g of pure polyamic acid solid is dissolved in 205ml of water, 1.0ml of ammonia water is added, in the step (b), 35ml of weak acid solution is taken, 1.0g of surfactant is taken, 10ml of methyltrimethoxysilane is taken, 5ml of polyamic acid salt solution is taken, the temperature of an oven is 63 ℃, in the step (c), the drying temperature is 285 ℃, the drying pressure is 10MPa, and the drying time is 12 hours, all the materials are the same as in the example 1.
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make modifications and alterations without departing from the scope of the present invention.
Claims (10)
1. The preparation method of the polymethylsilsesquioxane-polyimide composite aerogel material is characterized by comprising the following steps of:
(a) dissolving a diamine compound and a dianhydride compound in a solvent in sequence, stirring uniformly, adding water to precipitate polyamide acid precipitate, washing the obtained polyamide acid precipitate for a plurality of times, freeze-drying to obtain pure polyamide acid solid, dissolving the pure polyamide acid solid in water, adding ammonia water, and stirring to obtain a polyamide acid salt solution;
(b) taking a weak acid solution, sequentially adding a surfactant, methyltrimethoxysilane and a polyamic acid salt solution to obtain sol, and standing the sol in an oven to obtain polymethylsilsesquioxane-polyamic acid salt composite wet gel;
(c) and (c) replacing the composite wet gel obtained in the step (b) with alcohol for several times, and then performing alcohol supercritical drying to realize thermal imidization of polyamic acid salt, thereby finally obtaining the polymethylsilsesquioxane-polyimide composite aerogel.
2. The method for preparing polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in step (a), the diamine compound is selected from one or more of 4,4 ' -diaminodiphenyl ether, p-phenylenediamine, 2 ' -dimethylbenzidine and 2,2 ' -bis [4- (4-aminophenoxy) phenyl ] propane;
in the step (a), the dianhydride compound is selected from one or more of 3,3 ', 4, 4' -biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride or 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride;
in the step (a), the solvent is selected from one or more of 1-methyl-2-pyrrolidone or dimethylacetamide.
3. The method for preparing polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in the step (a), the molar ratio of the diamine compound to the dianhydride compound is 1: 1;
in the step (a), the adding amount ratio of the pure polyamic acid solid, the water and the ammonia water is (0.1-1.0) g, (20-25) ml and (0.3-1.0) ml.
4. The method for preparing the polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in the step (a), the temperature of freeze drying is-80 to-60 ℃, and the freeze drying is carried out twice, wherein the time of each freeze drying is 15 to 20 hours.
5. The method for preparing polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in the step (b), the weak acid is selected from one or more of hydrofluoric acid, glacial acetic acid and oxalic acid;
in step (b), the surfactant is selected from one or more of cetyltrimethylammonium chloride or cetyltrimethylammonium bromide.
6. The method for preparing the polymethylsilsesquioxane-polyimide composite aerogel material is characterized in that in the step (b), the addition amount ratio of the weak acid solution, the surfactant, the methyltrimethoxysilane and the polyamic acid salt solution is (20-35) ml, (0.2-1.0) g, (4-10) ml, (0.5-5) ml;
in the step (b), the concentration of the weak acid in the weak acid solution is 5-10 mmol/L.
7. The preparation method of the polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in the step (b), the temperature of the oven is set to be 45-65 ℃, and the standing time is 24-36 hours.
8. The method for preparing the polymethylsilsesquioxane-polyimide composite aerogel material according to claim 1, wherein in the step (c), the drying temperature is 265-290 ℃, the drying pressure is 10-14 MPa, and the drying time is 12-15 h.
9. A composite aerogel material prepared according to the method of any of claims 1-8.
10. Use of the composite aerogel material of claim 9.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002148254A (en) * | 2000-11-08 | 2002-05-22 | Sumitomo Chem Co Ltd | Polyimide resin analyzing method |
| WO2004009673A1 (en) * | 2002-07-22 | 2004-01-29 | Aspen Aerogels, Inc. | Polyimide aerogels, carbon aerogels, and metal carbide aerogels and methods of making same |
| CN1563149A (en) * | 2004-04-05 | 2005-01-12 | 南京工业大学 | Coupled reaction method for preparing nano hybridization material of polyimide-oxide of silicon |
| CN103055770A (en) * | 2013-01-08 | 2013-04-24 | 中国工程物理研究院激光聚变研究中心 | Preparation method of polyhedral oligomeric silsesquioxane-titanium dioxide composite aerogel |
| CN106947252A (en) * | 2017-03-22 | 2017-07-14 | 中国人民解放军海军工程大学 | Coated type polyimides strengthens the preparation method of aerosil |
| CN109593228A (en) * | 2018-11-16 | 2019-04-09 | 同济大学 | A kind of polyimides-organosiloxane aerogel composite and preparation method thereof |
| KR20190085426A (en) * | 2018-01-10 | 2019-07-18 | 인하대학교 산학협력단 | Method for Manufacturing Polyimide Aerogels cross-linked with amino-functionalized hollow mesoporous silica particles |
| CN110437492A (en) * | 2018-05-04 | 2019-11-12 | 中国科学院苏州纳米技术与纳米仿生研究所 | A kind of polyimide aerogels and the preparation method and application thereof with petal effect |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016019308A1 (en) * | 2014-07-31 | 2016-02-04 | Virginia Commonwealth University | Method for one-step synthesis, cross-linking and drying of aerogels |
| CN105713227A (en) * | 2016-04-18 | 2016-06-29 | 成都正威新材料研发有限公司 | Linear polyimide aerogel and preparing method thereof |
| CN110305360B (en) * | 2019-07-12 | 2022-02-18 | 航天特种材料及工艺技术研究所 | Deformable aerogel material and preparation method thereof |
-
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Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002148254A (en) * | 2000-11-08 | 2002-05-22 | Sumitomo Chem Co Ltd | Polyimide resin analyzing method |
| WO2004009673A1 (en) * | 2002-07-22 | 2004-01-29 | Aspen Aerogels, Inc. | Polyimide aerogels, carbon aerogels, and metal carbide aerogels and methods of making same |
| CN1563149A (en) * | 2004-04-05 | 2005-01-12 | 南京工业大学 | Coupled reaction method for preparing nano hybridization material of polyimide-oxide of silicon |
| CN103055770A (en) * | 2013-01-08 | 2013-04-24 | 中国工程物理研究院激光聚变研究中心 | Preparation method of polyhedral oligomeric silsesquioxane-titanium dioxide composite aerogel |
| CN106947252A (en) * | 2017-03-22 | 2017-07-14 | 中国人民解放军海军工程大学 | Coated type polyimides strengthens the preparation method of aerosil |
| KR20190085426A (en) * | 2018-01-10 | 2019-07-18 | 인하대학교 산학협력단 | Method for Manufacturing Polyimide Aerogels cross-linked with amino-functionalized hollow mesoporous silica particles |
| CN110437492A (en) * | 2018-05-04 | 2019-11-12 | 中国科学院苏州纳米技术与纳米仿生研究所 | A kind of polyimide aerogels and the preparation method and application thereof with petal effect |
| CN109593228A (en) * | 2018-11-16 | 2019-04-09 | 同济大学 | A kind of polyimides-organosiloxane aerogel composite and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| Synthesis of flexible silica aerogels using methyltrimethoxysilane(MTMS) precursor;A. Venkateswara Rao等;《Journal of Colloid and Interface Science》;20060327;第300卷;第279–285页 * |
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